Incandescent-lamp socket.



No. 783,295. PATENTED FEB. 21, 1905.

' N. MARSHALL.

INOANDESGBNT LAMP SOCKET.

APPLICATION IILED NOV. 26. 1904.

#9 lnueidvh' wM g 1 ll Stains Patented February 21, 1905.

ldriirienr @rrrcn NGRMAX h'lzillSllALL, OF NEWTON. MASSr Cl'lUSl llllS.

lhlQKiNDE$CENT=LAWlP- SOQKET- SPECIFICATION forming partof Letters Patent No. 783.295. dated February 21 1995.

Application filed November 26, 190 i. Serial No. 234,323.

in connection with incandescent lamps of the Edison type. Heretot'ore it has been customary in supplying Edison lamps to be used with T-H sockets to furnish an adapter for each lamp, which is applied to the T-H socket and is provided with terminals to cooperate with the terminals on the base of the Edison lamp. These adapters are provided with a screw-threaded central terminal for engaging the screw central terminal of the T-H socket andare held in place in the socket merely by the engage ment of these screw-threaded parts. in removing an old lamp from a socket the adapter is usually removed with the lamp, and it is necessary therefore to furnish an adapter for each Edison lamp which is to be used with a 'l-H socket, and this has been the practice.

in practicing the present invention 1 provide means for preventing the removal of the adapter after it has been once applied to a T-H socket, so that in removing thelamp it is removed 'trom the adapter, while the adapter remains as a permanent part of the 1 H socket, thereby permanently transforming it into a socket adapted to receive Edison lamps. The means for preventing the removal of the adapter from the socket is so formed that it does not interfere with the application of the adapter to-the socket, but prevents the rota-.

.Fig. 3.

Fig; 2 is a central view through the access of the adapter, and Fig. 3 is a vicwof the inner end of the adapter. l

As shown in the drawings, the adapter is provided with the usual metallic screw-shell A for engaging the outer metallic screw-terminal B et the lamp B and is also provided with a central internally-screw-threaded nietallic terminal C for engaging the screw-terminal D of the T-H socket l). The inner end of the metallic shell A is provided with a flat annular flange A, which engages the end of the porcelain base 1) of the socket when the adapter is screwed into position and forms the contact against which the switch-block of the key mechanism acts in the usual manner.-

At the inner edge'ot' this flange A. the shell is turned inward to form a rib A for engaging and determining the position of the'insulating isk E in which the terminal C is sooured: The adapter is also provided with the usual insulating-sleeve F surrounding the metallic screw-shell A. I

The means for preventing the removal of the adapter after it has been once screwed into place consists of one or more spring-catches Gr, formed by upsetting the metal from the flange A of the screw shell as indicated in These spring-catches yield as they engage the endot' the porcelain base D during the application of the adapter to the socket and spring outward'into one or more of the recesses in the end of the porcelain as the adapter is sore Wed home. The catch or catches then acts against the side of the recess in the porcelain to prevent rotation of the adapter in c direction to'un screw the adapter from the socket,and thus prevents the removal of the adapter and makes it a permanent partor attachment to the socket, so that the lamp B may be removed without danger of removing in Fig. 1 one of the catches G is shownin posi-- tron-1n the recess of the porcelain base inthe adapter and a' new lnmp introduced.

which thecentral terminal is located, where it will act against the side D of the recess to prevent the backward rotation of the adapter.

The catches G are so arranged upon the flat flange A' that they will not interfere with the action at the switch-block upon the flange, the

catches being arranged within the part of the of the key mechanism. v

By means of the adapters embodying my invention Thomson-Houston sockets which have been once supplied with an adapter become permanently adapted for use in connection with Edison lamps, and thereis no necessity thereafter for supplying adapters with lamps to be used with such sockets.

What I claim, and desire to secure by Letters Patent, is-

1. The combination with an incandescentlamp socket provided with acentral screw-terminal, and an adapter provided with a cooperating screw-terminal, and a screw-shell, of means for preventing the removal of the adapter from the socket when once applied thereto. h

2. The combination with an incandescentlamp socket provided with a central screw-terminal, and an adapter provided with a cooperating screw-terminal, and a screw-shell, of means for preventing a backward rotation of sition on the central terminal.

3. An adapter provided with a central screwtermmal for engaging the central terminal of a Thomson-Houston socket, ascrew-shell, and

means for preventing the removal of the adapter from the socket when it has been once applied thereto.

4:. .An adapter provided with a central screwthreaded terminal for engaging the central terminal of a Thomson-Houston socket, a screwshell, and one or more sprin'gcatches for preventing backward rotation of the adapter after it has been applied to the socket.

5. An adapter provided with acentral screwthreaded terminal, a screw-shell, an annular contact-flange, and one or more spring-catches on the flange. I i

6. An adapter provided with a central screwthreaded terminal, a screw-shell, an annular contact-flange, and one or morecatches upset from the metal of the flange.

In witness whereof I have afiixed my signature in presence of two witnesses.

NORMAN MARSHALL. Witnesses:

ARTHUR P. MORLEY, MAY E. LYNCH. 

